4.19-stable review patch. If anyone has any objections, please let me know.
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From: Tony Lindgren tony@atomide.com
commit 34539b442b3bc7d5bf10164750302b60b91f18a7 upstream.
The am335x devices started producing boot errors for resetting musb module in because of subtle timing changes:
Unhandled fault: external abort on non-linefetch (0x1008) ... sysc_poll_reset_sysconfig from sysc_reset+0x109/0x12 sysc_reset from sysc_probe+0xa99/0xeb0 ...
The fix is to flush posted write after enable before reset during probe. Note that some devices also need to specify the delay after enable with ti,sysc-delay-us, but this is not needed for musb on am335x based on my tests.
Reported-by: kernelci.org bot bot@kernelci.org Closes: https://storage.kernelci.org/next/master/next-20230614/arm/multi_v7_defconfi... Fixes: 596e7955692b ("bus: ti-sysc: Add support for software reset") Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/bus/ti-sysc.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -978,6 +978,8 @@ static int sysc_reset(struct sysc *ddata val = sysc_read(ddata, offset); val |= (0x1 << ddata->cap->regbits->srst_shift); sysc_write(ddata, offset, val); + /* Flush posted write */ + val = sysc_read_sysconfig(ddata);
/* Poll on reset status */ offset = ddata->offsets[SYSC_SYSSTATUS];